Tea tree oil-containing chitosan/polycaprolactone electrospun nonwoven mats: a systematic study of its anti-bacterial properties in vitro

This study demonstrates a facile and general method developed to prepare a free-standing chitosan/polycaprolactone nonwoven mat (CS/PCLNM) using an electrospinning system equipped with a metallic frame with an air gap. All nonwoven mats are composed of polycaprolactone microfibres coated with a layer of CS or tea tree oil containing-CS (TTO-CS/PCLNM). Four bacteria commonly associated with human skin flora infections or hospital-acquired infections were chosen as the targets for our in vitro anti-bacterial susceptibility testing (P. aeruginosa, M. luteus, S. pyogenes, and S. aureus). The bacteriostatsis ratios of the CS/PCLNM against above mentioned bacteria are -77.2%, -67.5%, 99.9%, and 86.4%, respectively. In addition, we find that the anti-bacterial ability of the CS/PCLNM is further promoted by incorporating a 100 mu L of TTO in its CS overlayer. After TTO incorporation, the produced TTO-CS/PCLNM shows anti-bacterial ability against all four strains of bacteria (P. aeruginosa: 99.8%, M. luteus: 12.8%, S. pyogenes: 96.7%, and S. aureus: 99.9%). In conclusion, the TTO-CS/PCLNM exhibits broader anti-bacterial spectrum than that of the CS/PCLNM toward commonly seen skin flora.